// 导出页面为PDF格式
import html2Canvas from 'html2canvas'
import JsPDF from 'jspdf'
export default {
  install(Vue, options) {
    // 分页做法
    Vue.prototype.getPdfByPage = function () {
      var title = this.htmlTitle;
      html2Canvas(document.querySelector('#pdfDom'), {
        allowTaint: true,
        scale: 2
      }).then(function (canvas) {
        let contentWidth = canvas.width;
        let contentHeight = canvas.height;
        let pageWidth = 595.28; // 设置页面宽度为PDF的宽度
        let pageHeight = pageWidth / contentWidth * contentHeight; // 计算页面高度，保持比例
        let leftHeight = contentHeight;
        let position = 0;
        let imgWidth = pageWidth;
        let imgHeight = pageWidth / contentWidth * contentHeight;
        let pageData = canvas.toDataURL('image/jpeg', 1.0);
        let PDF = new JsPDF('', 'pt', [pageWidth, pageHeight]); // 设置PDF的宽高
        if (leftHeight < pageHeight) {
          PDF.addImage(pageData, 'JPEG', 0, 0, imgWidth, imgHeight);
        } else {
          while (leftHeight > 0) {
            PDF.addImage(pageData, 'JPEG', 0, position, imgWidth, imgHeight);
            leftHeight -= pageHeight;
            position -= pageHeight;
            if (leftHeight > 0) {
              PDF.addPage();
            }
          }
        }
        // 删除空白页
        let pageCount = PDF.internal.getNumberOfPages();
        for (let i = pageCount; i > 1; i--) {
          PDF.deletePage(i);
        }
        PDF.save(title + '.pdf');
      });
    };
    // 不分页做法
    Vue.prototype.getPdfByNoPage = function () {
      var title = this.htmlTitle;
      html2Canvas(document.querySelector('#pdfDom'), {
        allowTaint: true,
        scale: 2
      }).then(function (canvas) {
        let contentWidth = canvas.width;
        let contentHeight = canvas.height;
        let pageHeight = contentWidth / 592.28 * 841.89;
        let leftHeight = contentHeight;
        let position = 0;
        let imgWidth = 595.28;
        let imgHeight = 592.28 / contentWidth * contentHeight;
        let pageData = canvas.toDataURL('image/jpeg', 1.0);
        let PDF = new JsPDF('', 'pt', 'a4');

        if (leftHeight < pageHeight) {
          PDF.addImage(pageData, 'JPEG', 0, 0, imgWidth, imgHeight);
        } else {
          while (leftHeight > 0) {
            PDF.addImage(pageData, 'JPEG', 0, position, imgWidth, imgHeight);
            leftHeight -= pageHeight;
            position -= 841.89;
            if (leftHeight > 0) {
              PDF.addPage();
            }
          }
        }

        PDF.save(title + '.pdf');
      });
    };
  }
}    